The PTU module contains separate sensors for pressure, temperature, and humidity measurement.
The PTU module includes:
- Capacitive silicon BAROCAP sensor for pressure measurement
- Resistive thin-film Pt1000 sensor for air temperature measurement
- Capacitive thin-film polymer HUMICAP R2 sensor for humidity measurement
In case of capacitive sensors, the measurement principle of the transmitter is based on an advanced RC oscillator and reference capacitors against which the capacitance of a sensor is continuously measured. The resistive Pt1000 sensors are measured with a voltage divider circuit incorporating a reference resistor and a stable voltage source.